Field of the Invention
The present invention relates to a robot diagnosing method, and particularly to a robot diagnosing method of detecting a deviation amount caused by a lost motion.
Description of Related Art
A robot diagnosing method of detecting a deviation amount caused by a lost motion has been known. Such diagnosing method is used for a wafer conveying apparatus described in the specification of Japanese Laid-Open Patent Application Publication No. 2009-49251.
The wafer conveying apparatus of the above publication repeatedly performs an operation of detecting a wafer at target positions that are arbitrary positions offset from a teaching command position, until the wafer moves out of a detection range of a wafer edge position detection sensor. Then, the wafer conveying apparatus stores the generated target positions and positions to which a transfer arm is actually moved. After all information pieces regarding X-direction and Y-direction positions from the teaching command position are collected, an arm drive control portion produces a correction table based on position errors that are differences between the target positions of the offset operations and the positions to which the transfer arm is actually moved and which are determined based on results of center positions of the wafer.